Defect in amino acid metabolism may result in

Options

A. Porphyria
B. Phenylketonuria
C. Wilson's disease
D. Tay sach's disease

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks about the consequences of a defect in amino acid metabolism. We need to identify which of the given options is a result of such a defect.

2. **Analyzing the Options:**
The options provided are:
- A) Porphyria
- B) Phenylketonuria
- C) Wilson disease
- D) Tay-Sachs disease

3. **Identifying the Correct Disorder:**
- **Porphyria:** This condition is related to the accumulation of porphyrins, not amino acids. Therefore, it is not caused by a defect in amino acid metabolism.
- **Phenylketonuria (PKU):** This is a well-known inborn error of metabolism caused by a defect in the enzyme phenylalanine hydroxylase, which is responsible for converting phenylalanine to tyrosine. A defect in this enzyme leads to the accumulation of phenylalanine, which can cause intellectual disabilities and other health issues.
- **Wilson disease:** This disorder is related to copper accumulation in the body, particularly in the liver and brain, and is not related to amino acid metabolism.
- **Tay-Sachs disease:** This is a genetic disorder that results in the destruction of nerve cells in the brain and spinal cord, primarily due to a deficiency in the enzyme Hexosaminidase A, which is not directly related to amino acid metabolism.

4. **Conclusion:**
Based on the analysis, the correct answer is **B) Phenylketonuria**, as it is directly linked to a defect in amino acid metabolism.